Dong Xiaolin, Huang Yaling, Pei Yanfang, Chen Ling, Tan Tianliang, Xiang Fayun, Li Chuanren, Fu Lijun
Department of Entomology, MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), College of Agriculture, Yangtze University, Jingzhou, China.
Department of Biotechnology, Key Laboratory of Ecological Environment and Information Atlas (Putian University) Fujian Provincial University, Putian, Fujian, China.
J Econ Entomol. 2024 Dec 28;117(6):2413-2424. doi: 10.1093/jee/toae239.
Anthocyanins are secondary metabolites which act as diverse functions during plant growth. Insects can discriminate host plants by their sensitive gustatory systems. It is hypothetical that chemosensory proteins (CSPs) play a crucial role in regulating this behavioral process. However, the underlying molecular mechanisms remain obscure. In the present study, we characterized a CSP SlitCSP8 from the Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae). Quantitative real-time-polymerase chain reaction analysis demonstrated that SlitCSP8 was mainly expressed in the head of the 7th S. litura larvae, especially labrum. Further, recombinant SlitCSP8 was obtained using bacterial expression system. Fluorescence competitive binding assays demonstrated that the purified SlitCSP8 exhibited a strong binding affinity to anthocyanins, a natural compound derived from the host plant. Silencing SlitCSP8 through RNAi significantly reduced the sensitivity of S. litura larvae to anthocyanins-treated leaf disks, the development from larva to pupae was not affected. These data provide insight into the molecular basis that CSP8 can detect anthocyanins in host plants by chemosensory system of insects. It can be further used in designing novel optimal food attractant targeting to the CSPs for pest control.
花青素是植物生长过程中发挥多种功能的次生代谢产物。昆虫能够通过其敏感的味觉系统辨别寄主植物。据推测，化学感受蛋白（CSPs）在调节这一行为过程中起着关键作用。然而，其潜在的分子机制仍不清楚。在本研究中，我们对斜纹夜蛾（鳞翅目：夜蛾科）的一种CSP——SlitCSP8进行了表征。实时定量聚合酶链反应分析表明，SlitCSP8主要在斜纹夜蛾7龄幼虫的头部表达，尤其是上唇。此外，利用细菌表达系统获得了重组SlitCSP8。荧光竞争结合试验表明，纯化后的SlitCSP8对花青素（一种来源于寄主植物的天然化合物）具有很强的结合亲和力。通过RNA干扰沉默SlitCSP8显著降低了斜纹夜蛾幼虫对用花青素处理过的叶盘的敏感性，但其从幼虫到蛹的发育不受影响。这些数据为CSP8通过昆虫化学感受系统检测寄主植物中的花青素提供了分子基础。它可进一步用于设计针对CSPs的新型最佳食物引诱剂以控制害虫。
